Adjustable chip breaker



Jan. 10, 1961 I R. E. NOVKOV 2,967,345

' ADJUSTABLE CHIP BREAKER Filed Oct. 8, 1958 IN V EN TOR.

FIG. 5 QM ATTORNEY United States Patent ADJUSTABLE CHIP BREAKER RaymondE. Novkov, Akron, Ohio, assignor to Manchester Machine & Tool Company,Akron, Ohio, a corporation of Ohio Filed Oct. 8, 1958, Ser. No. 766,120

'5 Claims. (Cl. 29-96) This invention relates to the art of cuttingtools and in particular has reference to the adjustment ofchipcontrolling elements that are normally employed in association withsuch cutting tools.

In the prior art of cutting tools, it has long been known that the chipthat is cut from a revolving stock can be controlled as to size andlength by use of a chip breaker. Normally, chip breakers of this typeinclude a wear surface that is inclined to the cutting edge so that thechip will, in effect, roll up the inclined surface to form into a spiralthat is easily removed.

In the art of chip breaking, it has been found that the perfect chipwill resemble a figure 9 so as to have one complete curl provided in thesame before breaking of the chip. While it is entirely possible toemploy chip breakers of the known prior art in machining operationsinvolving continuous operation on the article, it has been found that inmany cases where the cutting tool is repetitively employed on successivepieces of stock, that the hardness or brittleness of the stock willchange from piece to piece with the result that it frequently happensthat the chip formation will also change during the machining operation.

The above condition can result in a detrimental operation of the cuttingtool since a chip that is too long in nature is disadvantageous, while achip that breaks off too quickly, so as to be extremely short, is alsodisadvantageous.

In the prior art, when a situation of the above described type has beenencountered, it has been found necessary to stop the machine and resetthe angle, or distance, of the chip breaker, with this normally beingaccomplished by loosening the screws that retain the same in place,followed by repositioning of the device so as to cause a different typeof chip to be created.

It is, of course, manifest that the foregoing type of adjustment is, atbest, time consuming and, accordingly, costly. Additionally, thisprior-art method has the disadvantage that the same can only accomplishthe desired result by cut-and-try methods, with the result'that, evenupon resetting of the chip breaker angle, the chip created may not besatisfactory, with the result that one or more additional resettingattempts must be made before proper accuracy is obtained.

In copending application, Serial Number 688,306, filed October 4, 1957,by Raymond E. Novkov, there was provided a cutting tool that featured achip breaker that was rotatably journaled on the tool body per se, withmeans being provided to facilitate rotation of the chip breaker elementrelatively of the tool body during the cutting operation. In this mannerthe position of the chip breaker could be adjusted from piece to pieceduring operation of the tool so that a constantly uniform type of chipcould be obtained regardless of the consistency of the stock that wasencountered.

While a chip breaking device of this general characteristic has beenfound to be satisfactorily operative,

the same has been disadvantageous in that the method of rotating thechip breaker was relatively expensive, with the result that the use wasavoided wherever possible. Specifically, in the above reference tocopending application, rotational or relative movement of the chipbreaking element with respect to the tool was facilitated by worm-geartype of connection, with the chip breaking element having a pinion thatis journaled in the body, with the pinion meshing with a worm gear so asto effectuate rotation around a given point.

In this regard, it was frequently found that, in addition to beingcostly, the above type of arrangement was susceptible to clogging, withthe result that the tool had to be frequently disassembled for cleaningpurposes.

In copending application, Serial No. 736,361, filed May 19, 1958, byRaymond E. Novkov, there was disclosed an improved type of chip breakerthat obviaLed certain of the aforementioned disadvantages of the priorart by providing a thread-and-block type of advancing mechanism foreffectuating shifting of the chip breaking element. Specifically, thedevice employed a pin member that projected from a block rotatablyjournaled about the tool. holder, with the block being disposed in waysso that upon rotation of the cylindrical member, the block and pin wouldadvance axially thereof to effectuate a shifting of the chip breakerelement.

While this improved shifting mechanism has greatly enhanced theusability of the above device, it has been found that the same in no wayenhances the overall life of the chip breaker element itself, with theresult that the replacement of the chip breaker element has become animportant factor due to the necessity of contouring the same to permitcorrect reception of the same on the tool holder.

In this regard, it has been found that the frontal surface of the chipbreaking element is most susceptible to wear; and accordingly, it hasbeen discovered that if the normal frontal edge thereof is undercut andprovided with a high-wear type of replaceable insert, the overall lifeof the chip breaker will be greatly enhanced. Additionally, thesubstitution of a harder material in this critical wear region hasresulted in a further advantage in that the component parts can bearranged so that the bit is retained in place in its seat principally bythe hardened insert. In this fashion, a lesser area of contact occursbetween the clamping element and the bit; and thus, a lesser amount ofrotational force is required to overcome the frictional contact and movethe clamping member and chip breaking member relatively of the bit,while still serving to retain the same in place within its seat. Evenfurther, the use of bolts to secure the insert in place eliminates thepossibility of loss thereof during changing of the cutting bit forexample.

In addition, it has been further found that, while a way type of guidingarrangement can be provided for use in straight line operations, a moreefficient and satisfactory result will be obtained if the combined chipbreaker and clamping element is moved through its straight line path ofmovement by a rib and groove type of connection. This is specificallytrue because of the fact that the transversely extending rib preventsrotationally shifting of the chip breaker during use and furtherprevents movement of the chip breaker away from a single way type ofconstruction as shown in the above referred to copending application.

Accordingly, production of an improved type of chip breaker employingthe above features becomes the principal object of this invention, withother objects of this invention becoming more apparent upon reading ofthe of the accompanying drawings.

Of the drawings:

Figure 1 is a perspective view of the improved chip breaking device.

Figure 2 is a perspective view taken from a different point and beingpartly broken away and in section to show the internal construction ofthe device.

Figure 3 is a vertical section taken on the lines 3, 3 of'Figure 1.

Figure 4 is a vertical section taken on the lines 4, 4 of Figure 2.

Figure 5 is a horizontal section taken on the lines 5 5 of Figure 3.

Figure 6 is a perspective view of the chip breaking insert.

Referring now to the drawings and in particular to Figure 1 thereof, itwill be seen that the improved tool, generally designated by the numeral19, includes a shank portion 11 and a head portion 12, with the headportion 12 being contoured for reception of one or more cutting bits 13and a combination clamping and chip breaking element 14, and with thecombination clamping and chip breaking element 14 being movable betweenthe full and chain dotted line positions of Figure 3 upon operation ofadjustment means 16, as will hereinafter be described.

Considering first the structure of the head portion 12, it will be seenthat the same includes a front face 20, a top face 21 and a rear face 22(see Figure 3) that each terminates at one end thereof at an end face 23as is clearly shown in Figure 1 of the drawings. In this regard andreferring next to Figure 2, a seat 24, having convergent sides 24a and24b, is shown defined by the front, top and end surfaces 20, 21 and 23of head 12 so as to define a seat or pocket within which the cutting bit13 may be received, with both the cutting bit 13 and the seat 24 beingillustrated in the preferred embodiment of the invention as beingtriangular in plan so as to facilitate the use of a six side cutting bitof the type shown in the drawings. In this regard, the usual clearancehole 24c is preferably provided at the apex of the triangularly shapedpocket 24 for the purpose of providing clearance in this regard.

For the purpose of shiftably mounting the combination clamping and chipbreaker element 14in coplanar relationship with top surface 21, the same(top surface 21) is provided with a tapped aperture that is spacedinwardly from the end surface 23, so as to receive therein the threadedend of a bolt 26, with this bolt 26 having its upper shank portiondisposed within a slot 27 that is provided in a combination clamping andchip breaking element 14, as indicated in Figures 1, 3 and 5- of thedrawings. In this manner, backing off of the screw 26 will permitrelease of the coplanar engagement between the combination clarnping andchip breaking elemeat 14 and top surface 21 so as to permit the removalof the cutting bit 13 from seat 24 for sharpening or other usualpurposes upon removal of bolt 26. If desired, the construction andthreading arrangement of the bolt 26 may be such that the same may havean integral flange that will cause the combination clamping and chipbreaking element 14 to move away from face 21 upon counter-clockwisemovement (Figures 1 and 2) of the bolt 26, as by inserting a wrench inopening 26a thereof. Preferably, however, a conventional bolt isemployed so as to cause clamping of the bit between combination clampingand chip breaking element 14 and pocket 24 upon drawing up of the same.

Referring next to Figure 2 of the drawings, it will be further seen thatthe face 21 is further provided with a transversely extending raised ribportion 28 that extends transversely thereof between the opposed planarsurfaces and 22 for coaction with the combination clamping and chipbreaker element 14, as Will hereinafter be described. Additionally, itwill be seen from Figures 2 and 3 of the drawings that the head portion12 is further provided with a transverse bore 30 that interconnectsfront and rear surfaces 20 and 22 and which has the central portionthereof defined by an enlarged opening 31; the arrangement being suchthat the enlarged opening 31 will open into top surface 21 to permitpositioning and withdrawal of the adjustment means, as will now bedescribed.

In this regard and considering next the structure of the adjustmentmeans 16 per se, it will be seen that the same includes a threadedmember 40 having its axial ends 41 and 42 loosely jotirnaled within theopposed portions of bore 30 so that a head portion 43 thereof can beretained against counter-bore 30a of bore 30 by use of the conventionalretaining rings 44, 44. In this manner, the bolt 40 will merely looselyturn within the slots 30, 30 upon rotation thereof and will not moveaxially of bore 30. Surrounding the threaded member 40 is a block 45that has an internally threaded bore that permits threaded reception ofblock 45 around the threaded shaft 40. In this regard, the external wallsurfaces 45a of the block normally contact the opposed wall surfaces31a, 31a of opening 31 and in this manner, the block 45 is preventedfrom rotating about the shaft 40, with the result that the block 45 willshift relatively of opening 31 upon rotation of shaft 40, with thiscondi tion being shown in full and chain-dotted lines in Figure 3 of thedrawings. To the end of imparting shifting movement to the combinationclamping and chip breaking element 14, the block 45 further'includes aprojecting pin 50 that is received, as best shown in Figure 3, withinanappropriate undercut 51 that is defined by the undersurface 14a ofcombination clamping and chip breaking element 14.

In addition to the aforementioned component parts and referringparticularly to Figure 5, the surface 14:: of combination clamping andchip breaking element 14 is provided with an undercut pocket 55,preferably of triangular configuration so as to be defined by convergentwall sections 55a and 55b. Received within this pocket is anappropriately contoured, hardened chip breaker element member, generallyindicated by the numeral 60, with this member 60 preferably projectingslightly beyond the front edge surface 14b of the chip breaker so as toserve as a wear surface for the frontal region of the chip breaker.Also, and as shown in Figures 4 and 5, the chip breaker 60 is preferablydetachably attached with respect to pocket 55 by use of a counter-sunkbolt 61; and in this regard, it is to be understood that the inventioncontemplates that the frontal edge 60:: of the insert can be eitheraligned with, recessed with respect to, or projecting beyond the frontaledge surface 14b of the combination clamping and chip breaking element14. Additionally, it is also to be understood that the surface 60b ofthe insert could also project, as shown in Figure 4, beyondthe surface14:: so as to permit the surface 605 to engage the bit 13. It is also tobe understood that a' flush or recessed arrangement could also beemployed in this regard. Also and as best shown inFigures 1 and 3, thecombination clamping and chip breaking element 14 further includes atransversely extending groove 65 that coacts with the raised rib 28, asclearly shown in Figure l, to permit sliding movement of the combinationclamping and chip breaking element 14 transversely of the head 12.

In use or operation of the improved chip breaker, it will first beassumed that the component parts have been assembled as indicated in thedrawings, with the chip breaking insert 60. first having been positionedin pocket 55 and'secured thereto by bolt 61, as shown in Figures 4 and5. With, the chip breaker thus assembled, the same. can be positioned sothat the pin 50 is received in slot 51 and at this time, the bolt; 26may be turned so that a light frictional contact is created between thebit 13. and the chip breaker 60, with the preferred embodilllcnt of theinvention contemplating that the contact be one of coplanar engagementbetween the surfaces 60b and 13a of inserts 60 and 13 respectively. Inthis condition, upon rotation of the bolt 40, as by positioning of aturning tool slot 40a, the pin 50 will be shifted transversely ofsurface 21, with the result that a corresponding shifting of thecombination clamping and chip breaking element 14 will occur. In thisregard, it is to be understood that in normal instances, it will not benecessary to adjust the bolt 26 to effectuate such shifting, due to thefact that the shifting force imparted to element 14 by pin 51 cannormally overcome any frictional contact that may exist between the headof the bolt 26 and the element 14. However, in severe instances, it maybe necessary to first slightly back oflf the screw 26 before rotatingthe threaded member 40.

If it is desired to replace the insert 13, it is merely necessary thatthe bolt 26 be loosened, at which time the insert can be withdrawntransversely of the pocket and turned to expose a new cutting edge.Similarly, if the insert 60 becomes damaged, it is merely necessary thatcombination clamping and chip breaking element 14 be removed, followedby removal of screw 61, at which time the insert 60 can be freelyremoved and turned within pocket 55 to present a new wear surface. Inthis regard, the edges of the insert 60 are preferably tapered as at 60cso as to present an inclined surface, as shown in Figure 1 of thedrawings. It accordingly follows that in such instances, the walls 55aand 55b would be complementary tapered so as to permit proper setting ofbit 60 in pocket 55.

It will be seen from the foregoing how there has been provided a new andimproved type of adjustable chip breaker having improved wearingproperties has been provided. It has been shown how the chip breakingsurfaces can be adjusted with respect to the cutting edge of the toolwithout the need for touching the same; and accordingly, it is manifestthat applicants improved tool can be adjusted while hot because of thisfeature.

While a full and complete disclosure of this invention has been setforth in accordance with the dictates of the patent statutes, it is notintended that the application be so limited. Accordingly, whereappropriate different materials or shapes may be substituted without theexercise of invention. As a representative example, it is to be knownthat surface 21, for example, could be disposed in two different planeson opposite sides of rib 28. In this fashion, the combination clampingand chip breaking element 14 could be fulcrumed on rib 28 so that agreater clamping action would occur.

Accordingly, modifications of the invention may be resorted to withoutdeparting from the spirit herein or the scope of the appended claims.

This application is a continuation-in-part of copending application,Serial No. 688,306, filed October 4, 1957 by Raymond E. Novkov and isalso a continuation-inpart of copending application, Serial No. 736,361,filed May 19, 1958 by Raymond E. Novkov, now Patent No. 2,937,432 issuedMay 24, 1960.

What is claimed is:

l. A cutting tool of the character described, comprising; a tool holderhaving front and top planar surfaces that are undercut in localizedregions to define a tool pocket opening into said surfaces; a tool bitreceived in said tool pocket and having a cutting edge projecting beyondthe front surface of said body; a clamping member secured to said bodyand having a bottom surface overlying said top surface of said body insubstantial parallelism therewith, said clamping member also having afront edge surface that overlies said bit adjacent the projectingportion thereof; a chip breaker having a plurality of chip engagingsurfaces and being detachably connected with respect to said bottomsurface of said clamping member in indexable relationship therewith;said chip breaker having one of said chip engaging surfaces frictionallycontacting said bit adjacent said cutting edge, whereby said bit isretained in said pocket; said chip breaker being supported adjacent itspoint of connection with said clamping member against chip breakingforces received during cutting; and shifting means rotatably carried bysaid body at a spaced distance from said top surface and moving saidclamping member and said chip breaker as a unit towards and from saidcutting edge of said bit upon rotation of said means.

2. The device of claim 1 further characterized by the presence of guidemeans carried by said holder for guiding said clamping and chip breakermembers in a straight line path of movement upon operation of saidshifting means.

3. The device of claim 1 further characterized by the presence of guidemeans carried by said holder for guiding said clamping and chip breakermembers in a straight line path of movement upon operation of saidshifting means, said guide means including a groove and rib connectionbetween said clamping member and said top surface of said body.

4. A cutting tool of the character described, comprising; a tool holderhaving top and front surfaces that are undercut to define a tool seatopening into said surfaces; a. cutting bit received in said tool seat; aclamping element movably mounted on said tool holder and having a bottomsurface overlying said bit in substantially parallel relationshiptherewith; a chip breaker seat provided on said bottom surface of saidclamping element; a chip breaker element detachably secured in said chipbreaker seat of said clamping member and having a front edge surfacethat frictionally contacts said bit, whereby the same is retained insaid pocket; a pin member carried in said tool holder and projectingbeyond said top surface thereof and mechanically interlocking with saidclamping member; and reciprocable means carried in said tool holder andengageable with said pin member for reciprocating said pin transverselyof said top surface of said holder, whereby a correspondingreciprocation of said chip breaker and said clamping element relativelyof said top surface of said tool holder will occur.

5. The device of claim 4 further characterized by the fact that saidchip breaker seat and said chip breaker element received therein aretriangular in configuration.

References Cited in the file of this patent UNITED STATES PATENTS2,270,387 Spector Jan. 20, 1942 2,382,911 Pringle Aug. 14, 19452,791,825 Greenleaf May 14, 1957 2,799,079 Brigner July 16, 19572,883,737 Wilson Apr. 28, 1959 2,897,580 Huber Aug. 4, 1959 2,903,781Hudson Sept. 15, 1959 FOREIGN PATENTS 1,164,677 France May 19, 1958968,404 France Apr. 19, 1950 989,307 France May 23, 1951 60,931 FranceAug. 11, 1954 989,306 France May 23, 1951 1,084,955 France July 21, 19541,140,048 France Feb. 25, 1957

